Chemical crypsis in predatory ants

Summary The repellent responses of worker termites to ants are determined by the exocrine gland secretions of the latter. Specialized termite predators produce non-repellent aliphatic alcohols as the major components of their mandibular glands, whereas unspecialized con-generics usually produce repellent ketones and aldehydes.Acknowledgment. A C.A.S.E. Award (C.L.) from S.R.C. and the Centre for Overseas Pest Research is gratefully acknowledged as are facilities provided by the Ahmadu Bello University, Nigeria at Mokwa.     

Effect of dinitrophenol on the pattern of methionine transport along the small intestine of the rat

Zusammenfassung Der Transport desL-Methionins durch die Rattendarmwand wurde in vitro untersucht. Die Transportgeschwindigkeit im Verlaufe von 1 h ist am höchsten im unteren Jejunum und im oberen Ileum (Abschnitte 4, 5 und 6). DNP-verursachte Hemmung ist in diesen Darmabschnitten am stärksten, was das Verschwinden des Maximums bewirkt.     

Role of the pituitary in cyproheptadine-induced pancreatic beta-cell toxicity

Summary Hypophysectomized rats given cyproheptadine (40 mg/kg) for 10 days exhibited a loss of pancreatic immunoreactive insulin and ultrastructural changes in the cytoplasm of beta-cells. Sham-operated animals given cyproheptadine showed identical changes in pancreatic beta-cells except that cytoplasmic involvement progressed to the formation of large vacuoles. The pituitary is not directly involved with the cyproheptadine-induced depletion of pancreatic insulin but plays a role in the formation of large cytoplasmic vacuoles.Acknowledgments. This work was supported by U. S. Public Health Service, grant GM 12675.